I recently bought a TP-LINK TL-WDN4800 Dual Band Wireless N900 PCI Express Adapter,2.4GHz 450Mbps/5Ghz 450Mbps for my desktop computer which is about 30 ft down a hallway from my router, a TRENDnet 639GR(2.4Ghz only). I am getting only a "good" signal strength (3 of 5). The connection has poor(throughput) and is intermittent (keeps dropping to "limited connectivity" about every 20-30 mins). I live in an apartment building and there are about 25 other wireless networks on scan so I thought the issue might be interference but in the same location my laptop gets 5/5 signal strength, good throughput, and stable connections. I have reseated the card, tried several configurations of the antennas with no joy. I am trying to figure out if it might be a bad card or if i need to spend the money on a dual band 2.4/5Ghz router. Any help would really be appreciated.